Method of controlling water grass



United States Patent 3,246,974 METHOD OF CONTROLLING WATER GRASS Mervin E. Brokke, Richmond, Calif., and Chester L.

Dewald, Houston, Tex., assiguors to Stauifer Chemical Company, New. York, N.Y., a corporation of Delaware No Drawing. Filed Jan. 16, 1963, Ser. No. 251,738 1 Claim. (Cl. 71-2.6)

This invention relates to the use of certain compositions of matter as herbicides. vention regards the use of compounds of the general formula:

wherein R is a para-lower alkylphenyl or p-lower alkoxyphenyl radical and R is a cyclohexyl, phenyl or a substituted phenyl radical wherein said substituent is selected from the group consisting of halogen, lower alkyl, lower alkoxy and mixtures thereof. By lower alkyl and alkoxy is meant such radicals containing from one to five carbon atoms.

The compounds of the present invention and the method of preparing them are old and well known in the art and thus only their use as a herbicide is held to be new and novel.

One method of preparing the compounds of the present invention is to mix an appropriately substituted benzene sulfonyl chloride with an appropriately substituted aniline in the presence of pyridine. A water solution of base, such as sodium hydroxide or the like may be substituted for the solvent pyridine as this also readily picks up the liberated HCl from the reaction and leaves the desired compound.

The compounds of the present invention have been extensively tested both as pre-emergence herbicides and postemergence herbicides with excellent results. Pro-emergence herbicides are applied to a potential weed habitat either before or after seeding but before the crop emerges. It the herbicide is harmless to the desired crop, seeds or seedlings, but phytotoxic'to weed seeds or seedlings encountered, the crop grows in a weed-free environment. Post-emergence herbicides are applied after the crop and/ or weeds emerge from the soil and likewise must be harmless to the desired crop and phytotoxic with respect to the weeds encountered.

The phytotoxic compositions of the present invention may be applied to the weed habitat in any of the convenient forms well known to those skilled in the art. For instance, it can be dissolved in a solvent, such as acetone, or emulsified and sprayed onto the weed habitat; or it can be combined with a dry inert carrier and applied as a dust or as granules. The rates of application may vary widely depending on the results desired.

The phytotoxicity of the compounds of the present invention is shown by the results of the following testing methods.

Example 1 Seeds of water grass are planted in rows one-half inch deep in Santa Cruz sandy loam soil contained in 8 x 12" metal flats which are 2%" deep. The flats are watered after planting and the following day each flat is sprayed at rate of pounds of the compound under test in 80 gallons of solution per acre. A No. 152 DeVilbiss atomizer is used to spray the solution on the soil surface. Two weeks later the degree of weed control is determined by comparing the amount of germination and growth of each weed in the treated flats with the weeds in several untreated control flats.

The following chart shows the results of the test described supra.

' R-SO NI-IR More specifically, the present in- 7 3,246,974 Patented Apr. 19, 1966 Pre- Comemergence pound R R Water Grass N 0. Activity 1 4-mcthylphenyl... Oyclohexyl XX .do Z-methoxypheuyh. XXX

2-tlu0rophenyl,. X 4-methoxyphenyL. XX 2, 4-dimethylpheuyl XX x,x-diinethylphenyl XX Z-methyl-S-i-propylphenyl. X 2-ethylphenyl XX 2-chlorophenyl. XXX 2-methylphcnyl. XXX Phenyl XXX 2-1neLhyl-3-chloro XXX 3-mctliylphenyl XXX 4-fiuorophenyl, XXX XXX XX XX XX XXX XXX XXX do XXX 4-mcthylphenyl 2-chloro-4-nitrophenyl XX X indicates partial control. XX indicates good control. XXX indicates complete control.

Example 2 Seeds of water grass and rice were planted in Santa Cruz sandy loam soil contained in metal containers, as in Example 1. After growing for two weeks under greenhouse conditions the plants were four to six inches tall. The foliage was then sprayed using a DeVilbiss sprayer. This spray treatment was equivalent to a rate of 10 lbs. in gallons of solution/ acre. Two weeks after treatment the injury results to the water grass was recorded and are reported below. The rice was unalfected by the treatment.

RSO =N-HR Po St- C omemergence pound R R Water Grass No. Activity Cyclohexyl XX 2-methoxypheny1 XXX 2-fluorophcnyl XXX 4-methoxyphenyL. X 2,4-dimethylphenyL XXX x,x-dimethy1phenyl XXX Z-methyl-5-i-propylphenyl XXX Z-ethylphenyl XXX 2-chlorophenyl. XXX 2-methylphenyL XXX Phenyl X Z-rnethyl-3-chlorophenyl- XX 3-1nethylphenyl X 4-fluor0phenyl XXX B-methylphenyl. XXX 4-methylphenyl. XX ZA-dimethylphenyL XX 2,G-dimethylphcnyl X do 2-methylphenyl XXX 4-ethylphenyl 2-methoxyphenyl XXX d0 2-n ethy1phenyl XXX d0 2-ethylphenyl. XXX 24 4-rnethylphenyl 2-methoxy-5-chlorophonyl XX 25 4-methoxyphenyl 2-iluorophenyl XXX X indicates partial control. XX indicates good control. XXX indicates complete control.

We claim:

The method of controlling water grass compnising applying to said grass habitat a phy totoxic amount of a compound of the formula:

wherein R is a radical selected from the group consisting of para-lower alkylphenyl and para-lower alkoxyphenyl 3 4 t and R is a radical selected from the group consisting of FOREIGN PATENTS cyclo-hexyl, phenyl and substituted phenyl where-in said 23 970 12 1951 Germany.

substituent is selected from the group consisting of halogen, lower alkyl and lower alkoxy. OTHER REFERENCES 5 Fromm et al., Chemical Abstracts, vol. 46, col.

References Cited by the Examiner 83 15'( g), 1952.

UNITED STATES PATENTS 56s'gl"7s(yeg)ar1109v47et al., Chemical Abstracts, vol. 41, col. 2,964,568 12/ 1960 Kundiger et al 71-2.6 X

3,046,104 7/1962 Ehlers 712 10 LEWIS GOTTS, Primary Examiner. 

